gunsfandomcom-20200223-history
Belt feeder
A belt feeder or '''feeder/delinker '''is a part of the mechanism of a weapon that uses belts to carry cartridges. They are most commonly found on machine guns, though there are some examples of other weapons with them. The feeder is not necessarily a completely distinct mechanism: parts of it are often incorporated into the weapon's bolt group or block. History The first rapid-fire weapons with mechanical loading mechanisms mostly functioned via gravity feeders, using a hopper or feed guide to store ammunition: their only mechanical challenge was ensuring that only one cartridge entered the action at a time. Meanwhile, the first weapons using belts, chain rifles and chain revolvers, had completely manual feeding. The first patent for something that could be thought of as a mechanical belt feed was filed in 1876 by Fortune L. Bailey, describing a Gatling gun that fed from a belt, taking influence from the cartridge belts commonly worn by hunters. However, this system was not particularly similar to a modern belt feeder, as the rounds were fired while still on the belt. The first example of a true belt feeder was that of the Maxim gun. While belt feeders are usually only present on machine guns as they are the most common belt-fed weapons, a few other experimental or low-production weapons have employed them over the years, including the first version of the Thompson submachine gun, a single Krag-Jørgensen rifle, a Heckler & Koch G3 variant called the Volmer HK51 and the ARES-Olin AIWS. The lack of smaller examples of belt-fed weapons is because the size and weight of a belt feeder unit is non-trivial, and when scaled down too much the mechanism becomes overly fragile and malfunction-prone for very little meaningful increase in the gun's capabilities. Operation The purpose of any belt feeder is twofold: it must smoothly manage the belt's passage into and through the weapon, and strip and chamber rounds from it. There are two common arrangements for stripping ammunition, pull-out, push through (2-stage feed) and push through (single-stage feed). In a 2-stage feeding system the feeder grips the cartridge by the base or rim and pulls it out of the rear of the belt with a backwards motion, then aligns the round to place it into the weapon's action on the forward stroke. In a single-stage feed, the mechanism instead pushes the round out of the front of the belt on its forward stroke. , a single-stage feeding weapon with open-pocket disintegrating links.]] The type of stripping mechanism that can be used is determined by the structure of the belt: "closed-pocket" belts which retain the front end of the cartridge are only suited to 2-stage feeding, while "open-pocket" belts can use single-stage feeding. 2-stage feeding was most common on earlier machine guns, as the loop pockets of cloth ammunition belts were poorly suited to pushing the cartridge out forwards and would tend to snag on either the rim of the casing or parts of the feeding system. It is still used by several highly successful modern designs, in particular the PKM machine gun. The system also requires a mechanism to control and regulate the motion of the belt into the weapon, incorporating some type of stop to prevent issues such as the belt becoming misaligned or simply falling out of the gun. The most common method used is a set of feed pawls, claw-like assemblies powered by the weapon's action that prevents backward motion of the belt once mounted. Some weapons use static feed pawl mounts to advance and retain the belt, while on others the whole feed pawl assembly is mobile and swings sideways to align the round in the proper position to strip and chamber it, while drawing the belt into the gun so the next round is in feeding position as the gun completes a cycle. A less common option is to use a rotating sprocket to drive the belt along, interfacing with gaps in the belt in a similar manner to the drive sprocket of a set of tank treads. Loading a belt into a feeder also has several mechanical options: some weapons use a tab at the start of a belt that is pulled though the belt feed entry and out through the belt ejection port but most modern examples use a flip-up top cover with the feed pawl attached to it, with the user positioning the belt by hand in the feeding tray and then closing the cover to engage the feed pawls with the belt. In linkless feed systems the belt is effectively part of the feeding unit: usually these systems function like factory conveyor systems used in the production of items of similar shape to bullets (such as glass bottles), moving the cartridges from the magazine through an enclosed feeding chute. Gallery Category:Firearm parts or accessories